_csv compiles

3 files changed, 579 insertions, 413 deletions

diff --git a/modules/language/python/module/_csv.py b/modules/language/python/module/_csv.py
deleted file mode 100644
index 6db2d05..0000000
--- a/modules/language/python/module/_csv.py
+++ /dev/null
@@ -1,413 +0,0 @@
-(define-module (language python module _csv)
-  #:use-module (oop pf-objects)
-  #:use-module (langauge python list)
-  #:use-module (langauge python def)
-  #:use-module (langauge python yield)
-  #:use-module (langauge python for)
-  #:use-module (langauge python exceptions)
-  #:export (QUOTE_ALL QUOTE_MINIMAL QUOTE_NONNUMERIC QUOTE_NONE
-                      reader writer Error field_size_limit
-                      get_dialect register_dialect unregister_dialect
-                      list_dialects __doc__ Dialect))
-
-(define-python-class Error (Exception))
-
-(define-python-class Dialect ()
-  (define __init__
-    (lambda (self . x)
-      #f)))
-
-(define *field-size* (make-fluid 131072))
-(define field_size_limit
-  (case-lambda
-    (() (fluid-ref *field-size*))
-    ((x) (fluid-set! *field-size* x))))
-
-(define *dialects* (make-hash-table))
-(def (register_dialect nm (= val None) (** keyw))
-     (let ((newval (Dialect)))
-       (define-syntax-rule (set- x y z key default)
-         (set x 'key (hash-ref z (symbol->string 'key)
-                              (if (eq? y None)
-                                  default
-                                  (ref y 'key default)))))
-       (define-syntax-rule (setter x y z ((k def) ...))
-         (begin (set- x y z k def) ...))
-       
-       (setter newval val keyw
-                ((delimiter        ",")
-                 (doublequote      #t)
-                 (escapechar       None)
-                 (lineterminator   "\r\n")
-                 (quotechar        "\"")
-                 (quoting          'minimal)
-                 (skipinitialspace #f)
-                 (strict           #f)))
-
-       (hash-set! *dialects* nm newval)))
-
-
-       
-  (hash-set! *dialects* nm val))
-(define (get_dialect nm val)
-  (hash-ref *dialects* nm val None))
-(define (unregister_dialect nm)
-  (hash-delete! *dialects nm))
-
-(define (list_dialects)
-  (let ((ret '()))
-    (hash-for-each
-     (lambda (k v)
-       (set! ret (cons k ret)))
-     *dialects*)
-    (py-ist ret)))
-
-(define __doc__
-"CSV parsing and writing.
-
-This module provides classes that assist in the reading and writing
-of Comma Separated Value (CSV) files, and implements the interface
-described by PEP 305.  Although many CSV files are simple to parse,
-the format is not formally defined by a stable specification and
-is subtle enough that parsing lines of a CSV file with something
-like line.split(\",\") is bound to fail.  The module supports three\n
-basic APIs: reading, writing, and registration of dialects.
-
-
-DIALECT REGISTRATION:
-
-Readers and writers support a dialect argument, which is a convenient
-handle on a group of settings.  When the dialect argument is a string,
-it identifies one of the dialects previously registered with the module.
-If it is a class or instance, the attributes of the argument are used as
-the settings for the reader or writer:
-
-    class excel:
-        delimiter = ','
-        quotechar = '\"'
-        escapechar = None
-        doublequote = True
-        skipinitialspace = False
-        lineterminator = '\\r\\n'
-        quoting = QUOTE_MINIMAL
-
-SETTINGS:
-
-    * quotechar - specifies a one-character string to use as the
-        quoting character.  It defaults to '\"'.
-    * delimiter - specifies a one-character string to use as the
-        field separator.  It defaults to ','.
-    * skipinitialspace - specifies how to interpret whitespace which
-        immediately follows a delimiter.  It defaults to False, which
-        means that whitespace immediately following a delimiter is part
-        of the following field.
-    * lineterminator -  specifies the character sequence which should
-        terminate rows.
-    * quoting - controls when quotes should be generated by the writer.
-        It can take on any of the following module constants:
-
-        csv.QUOTE_MINIMAL means only when required, for example, when a
-            field contains either the quotechar or the delimiter
-        csv.QUOTE_ALL means that quotes are always placed around fields.
-        csv.QUOTE_NONNUMERIC means that quotes are always placed around
-            fields which do not parse as integers or floating point
-            numbers.
-        csv.QUOTE_NONE means that quotes are never placed around fields.
-    * escapechar - specifies a one-character string used to escape
-        the delimiter when quoting is set to QUOTE_NONE.
-    * doublequote - controls the handling of quotes inside fields.  When
-        True, two consecutive quotes are interpreted as one during read,
-        and when writing, each quote character embedded in the data is
-        written as two quotes")
-
-(define QUOTE_ALL        'all)
-(define QUOTE_MINIMAL    'minimal)
-(define QUOTE_NONNUMERIC 'nonumeric)
-(define QUOTE_NONE       'none)
-
-(def (reader csvfile (= dialect "excel") (** fmtparams))
-  (let*
-      ((dialect   (get-dialect dialect))
-            
-       (delimiter       (chr (py-get fmtparams "delimiter" e)
-                             (ref    dialect   'Delimiter  e)
-                             ","))
-         
-       (doublequote     (oor (py-get fmtparams "doublequote" e)
-                             (ref    dialect   'doublequote  e)
-                             #t))
-         
-       (escapechar      (chr (py-get fmtparams "escapechar" e)
-                             (ref    dialect   'escapechar  e)
-                             None))
-         
-       (lineterminator  (str (py-get fmtparams "lineterminator" e)
-                             (ref    dialect   'lineterminator  e)
-                             "\r\n"))
-         
-       (quotechar       (chr (py-get fmtparams "quotechar" e)
-                             (ref    dialect   'quotechar  e)
-                             "\""))
-         
-       (quoting         (oor (py-get fmtparams "quoting" e)
-                             (ref    dialect   'quoting  e)
-                             QUOTE_MINIMAL))
-         
-       (skipispace      (oor (py-get fmtparams "skipinitialspace" e)
-                             (ref    dialect   'skipinitialspace  e)
-                             #t))
-         
-       (strict          (oor (py-get fmtparams "strict" e)
-                             (ref    dialect   'strict  e)
-                             #f)))
-    (make-generator ()
-      (lambda (yield)
-       (for ((s : cvsfile)) ()
-         (let ((n (len s)))
-           (let lp ((i 0) (state #f) (l '()))
-             (let lp2 ((j i) (r '()))
-               (define-syntax-rule (raise- s)
-                 (if strict
-                     (raise s)
-                     (lp (+ j 1) r)))
-               (define (end j ch)
-                 (if (and (eq? state 'start)
-                          (eq? ch #\newline))
-                     (yield (py-list (reverse l)))
-                     (let* ((x (list->string (reverse r)))
-                            (x (if (eq? state 'numeric)
-                                   (string->number x)
-                                   x)))
-                       (if (eq? ch #\newline)
-                           (yield (py-list (reverse (cons x l))))
-                           (lp (+ j 1) 'start (cons x l))))))
-                   
-               (define (do-quotechar)
-                 (cond
-                  ((eq? state 'quote)
-                   (if doublequote
-                       (if (and (< (+ i 1) n)
-                                (equal? quotechar
-                                        (string-ref s (+ i 1))))
-                           (lp2 (+ j 2) (cons quotechar r))
-                           (end (+ j 1)))
-                       (end (+ j 1))))
-                    
-                  ((eq? state 'start)
-                   (if (or (eq? quoting 'minimal)
-                           (eq? quoting 'all)
-                           (eq? quoting 'nonnumeric))
-                       (lp (+ j 1) 'quote l)
-                       (raise- (Error "QOUTE_NONE supports no quoteing"))))
-                    
-                  (else
-                   (raise- (Error "wrong quoting found")))))
-
-               (define (do-whitespace ch)
-                 (cond
-                  ((eq? state 'start)
-                   (if skipispace
-                       (lp2 (+ i 1) r)
-                       (if (or (eq? quoting 'minimal)
-                               (eq? quoting 'none))
-                           (lp i 'normal l)
-                           (raise- (Error "whitespace outside quote")))))
-                  
-                  ((or (eq? state 'normal)
-                       (eq? state 'quote))
-                   (lp2 (+ i 1) (cons ch r)))
-                  
-                  ((eq? state 'nnumeric)
-                   (raise- (Error "whitespace in numeric field")))
-                  
-                  ((eq? state 'end)
-                   (raise- (Error "whitespace after quote")))))
-
-               (define (do-esc-qupote)
-                 (if (< (+ j 1) n)
-                     (let ((ch2 (string-ref s (+ j 1))))
-                       (cond
-                        ((and (eq? state 'quoting)
-                              (eq? ch2 quotechar))
-                         (lp2 (+ j 2)
-                              (cons quotechar r)))
-                          
-                        ((eq? ch2 delimiter)
-                         (lp2 (+ j 2)
-                              (cons delimiter r)))
-                                       
-                        ((eq? ch2 escapechar)
-                         (lp2 (+ j 2)
-                              (cons escapechar r)))
-
-                        (else
-                         (lp2 (+ j 2) r))))
-                     (raise- (Error "single escape ends line"))))
-
-               (define (do-escape)
-                 (cond
-                  ((eq? state 'start)
-                   (if (eq? quoting 'none)
-                       (lp j 'normal l)
-                       (raise- (Error "escapecharacter in nonquote"))))
-                    
-                  ((eq? state 'normal)
-                   (if (eq? quoting 'none)
-                       (do-esc-quote)
-                       (raise- (Error "escapecharacter in nonequote"))))
-                  
-                  ((eq? state 'numeric)
-                   (raise- (Error "escacpechar in numeric field")))
-                            
-                  ((eq? state 'quote)
-                   (do-esc-quote))
-
-                  ((eq? state 'end)
-                   (raise- (Error "escapechar after quote")))))
-
-               (define (do-delim ch)
-                 (cond
-                  ((or (eq? state 'start)
-                       (eq? state 'end))
-                   (end ch))
-
-                  ((eq? state 'quote)
-                   (if (eq? quoteing 'minimal)
-                       (raise-
-                        (Error "minimal quoting must quote delimiter"))
-                       (end ch)))
-                            
-                  ((eq? state 'normal)
-                   (end ch))
-
-                  ((eq? state 'numeric)
-                   (end ch))))
-
-               (if (< j n)
-                   (let ((ch (string-ref s i)))
-                     (cond
-                      ((or (eq? ch #\newline)
-                           (eq? ch #\return))
-                       (if (eq? state 'quote)
-                           (raise- (Error "missing end quote character"))
-                           (end #\newline)))
-                      
-                      ((or (eq? ch #\space) (eq? ch #\tab))
-                       (do-whitespace ch))
-                          
-                      ((eq? ch quotechar)
-                       (do-quotechar))
-
-                      ((eq? ch escapechar)
-                       (do-escape))
-
-                      ((eq? ch delimiter)
-                       (do-delim ch))
-                      
-                      ((eq? state 'numeric)
-                       (if (or (eq? ch #\.)
-                               (eq? ch #\-)
-                               (eq? ch #\e)
-                               (eq? ch #\E)
-                               (char-numeric? ch))
-                           (lp2 (+ j 1) (cons ch r))
-                           (raise- (Error "nonumeric in numeric field"))))
-                          
-                      ((eq? state 'start)
-                       (cond
-                        ((eq? quoting 'all)
-                         (raise-
-                          (Error
-                           "nonquoted field when all should be quoted")))
-                        ((eq? quoting 'nonnumeric)
-                         (lp j 'numeric l))
-                        (else
-                         (lp j 'normal  l))))
-
-                      ((or (eq? state 'quote) (eq? state 'normal))
-                       (lp2 (+ j 1) (cons ch r)))
-                          
-                      ((eq? state 'end)
-                       (raise-
-                        (Error
-                         "non delimeter after qouted field")))))
-                   (do-delim #\newline))))))))))
-              
-(define-python-class writer ()                                 
-  (define __init__
-    (lam (csvfile (= dialect "excel") (** fmt))
-         (set! dialect (if (string? dialect)
-                           (get_dialect dialect)
-                           dialect))
-         (set self 'csvfile csvfile)
-         (set self 'dialect dialect)))
-
-  (define writerow
-    (lambda (self l)      
-      (let*
-          ((dialect         (ref self 'dialect))
-            
-           (delimiter       (chr (py-get fmtparams "delimiter" e)
-                                 (ref    dialect   'Delimiter  e)
-                                 ","))
-         
-           (doublequote     (oor (py-get fmtparams "doublequote" e)
-                                 (ref    dialect   'doublequote  e)
-                                 #t))
-         
-           (escapechar      (chr (py-get fmtparams "escapechar" e)
-                                 (ref    dialect   'escapechar  e)
-                                 None))
-         
-           (lineterminator  (str (py-get fmtparams "lineterminator" e)
-                                 (ref    dialect   'lineterminator  e)
-                                 "\r\n"))
-         
-           (quotechar       (chr (py-get fmtparams "quotechar" e)
-                                 (ref    dialect   'quotechar  e)
-                                 "\""))
-           
-           (quoting         (oor (py-get fmtparams "quoting" e)
-                                 (ref    dialect   'quoting  e)
-                                 QUOTE_MINIMAL))
-         
-           (skipispace      (oor (py-get fmtparams "skipinitialspace" e)
-                                 (ref    dialect   'skipinitialspace  e)
-                                 #t))
-         
-           (strict          (oor (py-get fmtparams "strict" e)
-                                 (ref    dialect   'strict  e)
-                                 #f)))
-
-        (for ((x : l)) (r '())
-             (let/ec ret
-               (cons
-                (cond
-                 ((eq? quoting 'none)
-                  (let ((x (if (string? x) x (str x))))
-                    (if (has-escape-1 x)
-                        (if strict
-                            (raise (Error "None quoting and nonspecial chars"))
-                            (ret r))
-                        x)))
-                     
-                 ((eq? quoting 'nonnumeric)
-                  (let ((x (if (string? x) x (str x))))
-                    (if (is-numeric x)
-                        (number->string x)
-                        (quote-it x))))
-                
-                 ((eq? quoting 'none)
-                  (if (string? x)
-                      x
-                      (str x)))
-
-                 ((eq? quoting 'minimal)
-                  (let ((x (if (string? x) x (str x))))
-                    (if (has-escape-2 x) (quote-it x) x))))
-                r)
-               #:final
-               (write
-                (string-join
-                 (reverse
-                  (cons lineterminator r)) delim))))))))
diff --git a/modules/language/python/module/_csv.scm b/modules/language/python/module/_csv.scm
new file mode 100644
index 0000000..56e08da
--- /dev/null
+++ b/modules/language/python/module/_csv.scm
@@ -0,0 +1,578 @@
+(define-module (language python module _csv)
+  #:use-module (ice-9 control)
+  #:use-module (oop pf-objects)
+  #:use-module (language python list)
+  #:use-module (language python def)
+  #:use-module (language python yield)
+  #:use-module (language python for)
+  #:use-module (language python string)
+  #:use-module (language python exceptions)
+  #:export (QUOTE_ALL QUOTE_MINIMAL QUOTE_NONNUMERIC QUOTE_NONE
+                      reader writer Error field_size_limit
+                      get_dialect register_dialect unregister_dialect
+                      list_dialects __doc__ Dialect))
+
+(define-syntax-rule (aif it p . l) (let ((it p)) (if it . l)))
+
+(define-python-class Error (Exception))
+
+(define-python-class Dialect ()
+  (define __init__
+    (lambda (self . x)
+      #f)))
+
+(define *field-size* (make-fluid 131072))
+(define field_size_limit
+  (case-lambda
+    (() (fluid-ref *field-size*))
+    ((x) (fluid-set! *field-size* x))))
+
+(define *dialects* (make-hash-table))
+(define register_dialect
+  (lam (nm (= val None) (** keyw))
+       (let ((newval (Dialect)))
+         (define-syntax-rule (set- x y z key default)
+           (set x 'key (hash-ref z (symbol->string 'key)
+                                 (if (eq? y None)
+                                     default
+                                     (ref y 'key default)))))
+         (define-syntax-rule (setter x y z ((k def) ...))
+           (begin (set- x y z k def) ...))
+       
+         (setter newval val keyw
+                 ((delimiter        ",")
+                  (doublequote      #t)
+                  (escapechar       None)
+                  (lineterminator   "\r\n")
+                  (quotechar        "\"")
+                  (quoting          'minimal)
+                  (skipinitialspace #f)
+                  (strict           #f)))
+
+         (hash-set! *dialects* nm newval))))
+
+(define (get_dialect nm)
+  (hash-ref *dialects* nm None))
+(define (unregister_dialect nm)
+  (hash-remove! *dialects* nm))
+
+(define (list_dialects)
+  (let ((ret '()))
+    (hash-for-each
+     (lambda (k v)
+       (set! ret (cons k ret)))
+     *dialects*)
+    (py-list ret)))
+
+(define __doc__
+"CSV parsing and writing.
+
+This module provides classes that assist in the reading and writing
+of Comma Separated Value (CSV) files, and implements the interface
+described by PEP 305.  Although many CSV files are simple to parse,
+the format is not formally defined by a stable specification and
+is subtle enough that parsing lines of a CSV file with something
+like line.split(\",\") is bound to fail.  The module supports three\n
+basic APIs: reading, writing, and registration of dialects.
+
+
+DIALECT REGISTRATION:
+
+Readers and writers support a dialect argument, which is a convenient
+handle on a group of settings.  When the dialect argument is a string,
+it identifies one of the dialects previously registered with the module.
+If it is a class or instance, the attributes of the argument are used as
+the settings for the reader or writer:
+
+    class excel:
+        delimiter = ','
+        quotechar = '\"'
+        escapechar = None
+        doublequote = True
+        skipinitialspace = False
+        lineterminator = '\\r\\n'
+        quoting = QUOTE_MINIMAL
+
+SETTINGS:
+
+    * quotechar - specifies a one-character string to use as the
+        quoting character.  It defaults to '\"'.
+    * delimiter - specifies a one-character string to use as the
+        field separator.  It defaults to ','.
+    * skipinitialspace - specifies how to interpret whitespace which
+        immediately follows a delimiter.  It defaults to False, which
+        means that whitespace immediately following a delimiter is part
+        of the following field.
+    * lineterminator -  specifies the character sequence which should
+        terminate rows.
+    * quoting - controls when quotes should be generated by the writer.
+        It can take on any of the following module constants:
+
+        csv.QUOTE_MINIMAL means only when required, for example, when a
+            field contains either the quotechar or the delimiter
+        csv.QUOTE_ALL means that quotes are always placed around fields.
+        csv.QUOTE_NONNUMERIC means that quotes are always placed around
+            fields which do not parse as integers or floating point
+            numbers.
+        csv.QUOTE_NONE means that quotes are never placed around fields.
+    * escapechar - specifies a one-character string used to escape
+        the delimiter when quoting is set to QUOTE_NONE.
+    * doublequote - controls the handling of quotes inside fields.  When
+        True, two consecutive quotes are interpreted as one during read,
+        and when writing, each quote character embedded in the data is
+        written as two quotes")
+
+(define QUOTE_ALL        'all)
+(define QUOTE_MINIMAL    'minimal)
+(define QUOTE_NONNUMERIC 'nonnumeric)
+(define QUOTE_NONE       'none)
+
+(define e (list 'fail))
+
+(define-syntax-rule (bif it p a b)
+  (let ((it p))
+    (if (eq? it e)
+        b
+        a)))
+
+(define-syntax-rule (chr a b c)
+  (string-ref
+   (bif it a
+        it
+        (bif it b
+             it
+             c)) 0))
+
+(define-syntax-rule (oor a b c)
+    (bif it a
+         it
+         (bif it b
+              it
+              c)))
+
+(define-syntax-rule (str a b c) (oor a b c))
+
+(def (reader csvfile (= dialect "excel") (** fmtparams))
+  (let*
+      ((dialect   (get_dialect dialect))
+            
+       (delimiter       (chr (py-get fmtparams "delimiter" e)
+                             (ref    dialect   'Delimiter  e)
+                             ","))
+         
+       (doublequote     (oor (py-get fmtparams "doublequote" e)
+                             (ref    dialect   'doublequote  e)
+                             #t))
+         
+       (escapechar      (chr (py-get fmtparams "escapechar" e)
+                             (ref    dialect   'escapechar  e)
+                             None))
+         
+       (lineterminator  (str (py-get fmtparams "lineterminator" e)
+                             (ref    dialect   'lineterminator  e)
+                             "\r\n"))
+         
+       (quotechar       (chr (py-get fmtparams "quotechar" e)
+                             (ref    dialect   'quotechar  e)
+                             "\""))
+         
+       (quoting         (oor (py-get fmtparams "quoting" e)
+                             (ref    dialect   'quoting  e)
+                             QUOTE_MINIMAL))
+         
+       (skipispace      (oor (py-get fmtparams "skipinitialspace" e)
+                             (ref    dialect   'skipinitialspace  e)
+                             #t))
+         
+       (strict          (oor (py-get fmtparams "strict" e)
+                             (ref    dialect   'strict  e)
+                             #f)))
+    (make-generator ()
+     (lambda (yield)
+      (let/ec ret
+       (let ((iter (wrap-in csvfile)))
+         (let lp0 ((state 'start) (r '()) (l '()))
+           (define-syntax-rule (raise- s) (if strict (raise s)))
+           (define-syntax-rule (mk-wrap wrap state)
+             (define (wrap r)
+               (let* ((x (list->string (reverse r)))
+                      (x (if (eq? state 'numeric)
+                             (string->number x)
+                             x)))
+                 x)))
+           (mk-wrap wrap1 state)
+           (let ((s (catch #t (lambda () (next iter))
+                      (lambda x
+                        (cond
+                         ((or (eq? state 'line-end)
+                              (eq? state 'start)
+                              (eq? state 'field-end))
+                          (ret (reverse l)))
+
+                         ((or (eq? state 'numeric)
+                              (eq? state 'normal))
+                          (ret (reverse (cons (wrap1 r) l))))
+
+                         (else
+                          (raise- (Error "missing quote"))
+                          (ret (reverse (cons (wrap1 r) l)))))))))
+                         
+             (let ((n (len s)))
+               (let lp ((i 0) (state state) (r '()) (l l))
+                 (mk-wrap wrap state)
+                 (define-syntax-rule (raise- s)
+                   (if strict
+                       (raise s)
+                       (lp (+ i 1) state r l)))
+
+                 (define (end j ch)
+                   (if (eq? ch #\newline)
+                       (if (eq? state 'start)
+                           (begin
+                             (yield (py-list (reverse l)))
+                             (lp (+ j 1) 'line-end '() '()))
+                           (lp (+ j 1) state r l))
+                       (lp (+ j 1) 'start '() (cons (wrap r) l))))
+                     
+                 (define (do-quotechar ch)
+                   (cond
+                    ((eq? state 'doublequote)
+                     (lp (+ i 1) 'quote (cons ch r) l))
+                    
+                    ((and (pair? state) (eq? (car state) 'escape))
+                     (lp (+ i 1) (cdr state) (cons ch r) l))
+                        
+                    ((eq? state 'quote)
+                     (if doublequote
+                         (if (and (< (+ i 1) n)
+                                  (equal? quotechar
+                                          (string-ref s (+ i 1))))
+                             (lp (+ i 2) state (cons quotechar r) l)
+                             (lp (+ i 1) 'doublequote r l))
+                         (lp (+ i 1) 'field-end r l)))
+                          
+                    ((eq? state 'start)
+                     (if (or (eq? quoting 'minimal)
+                             (eq? quoting 'all)
+                             (eq? quoting 'nonnumeric))
+                         (lp (+ i 1) 'quote r l)
+                         (raise-
+                          (Error
+                           "QOUTE_NONE supports no quoteing"))))
+                    
+                    (else
+                     (raise- (Error "wrong quoting found")))))
+                 
+                 (define (do-whitespace ch)
+                   (cond
+                    ((eq? state 'doublequote)
+                     (raise-
+                      (Error "whitespace after end of quote")))
+                    
+                    ((pair? state)
+                     (lp (+ i 1) (cdr state) r l))
+                    
+                    ((eq? state 'start)
+                     (if skipispace
+                         (lp (+ i 1) state r l)
+                         (if (or (eq? quoting 'minimal)
+                                 (eq? quoting 'none)
+                                 (eq? quoting 'nonnumeric))
+                             (lp i 'normal r l)
+                             (raise-
+                              (Error "whitespace outside quote")))))
+                  
+                    ((or (eq? state 'normal)
+                         (eq? state 'quote))
+                     (lp (+ i 1) state (cons ch r) l))
+                  
+                    ((eq? state 'numeric)
+                     (raise- (Error "whitespace in numeric field")))))
+
+                 (define (do-esc-quote)
+                   (if (< (+ i 1) n)
+                       (let ((ch2 (string-ref s (+ i 1))))
+                         (cond
+                          ((and (eq? state 'quoting)
+                                (eq? ch2 quotechar))
+                           (lp (+ i 2) state (cons quotechar r) l))
+                           
+                          ((eq? ch2 delimiter)
+                           (lp (+ i 2) state (cons delimiter r) l))
+                                
+                          ((eq? ch2 escapechar)
+                           (lp (+ i 2) state (cons escapechar r) l))
+                              
+                          (else
+                           (lp (+ i 2) state r l))))
+                       (lp (+ i 1) (cons 'escape state) r l)))
+
+                 (define (do-escape ch)
+                   (cond
+                    ((pair? state)
+                     (lp (+ i 1) (cdr state) (cons ch r) l))
+                    
+                    ((eq? state 'doublequote)
+                     (raise
+                      (Error
+                       "no field or line end after quote, found esc")))
+                        
+                    ((eq? state 'start)
+                     (if (eq? quoting 'none)
+                         (lp i 'normal r l)
+                         (raise- (Error "escapecharacter in nonquote"))))
+                    
+                    ((eq? state 'normal)
+                     (if (eq? quoting 'none)
+                         (do-esc-quote)
+                         (raise- (Error "escapecharacter in nonequote"))))
+                  
+                    ((eq? state 'numeric)
+                     (raise- (Error "escacpechar in numeric field")))
+                            
+                    ((eq? state 'quote)
+                     (do-esc-quote))
+
+                    ((eq? state 'end)
+                     (raise- (Error "escapechar after quote")))))
+
+                 (define (do-delim ch)
+                   (cond
+                    ((eq? state 'start)
+                     (end i ch))
+                        
+                    ((eq? state 'quote)
+                     (lp (+ i 1) state (cons ch r) l))
+                        
+                    ((eq? state 'normal)
+                     (end i ch))
+
+                    ((eq? state 'numeric)
+                     (end i ch))))
+
+                 (define (do-line-end ch)
+                   (cond
+                    ((eq? state 'quote)
+                     (lp (+ i 1) state (cons ch r) l))
+                              
+                    ((pair? state)
+                     (lp (+ i 1) (cdr state) (cons ch r) l))
+                              
+                    ((eq? state 'field-end)
+                     (end i ch))
+                              
+                    ((eq? state 'line-end)
+                     (lp (+ i 1) 'line-end r l))
+
+                    (else
+                     (end i #\newline))))
+                            
+                 (if (< i n)
+                     (let ((ch (string-ref s i)))
+                       (cond
+                        ((or (eq? ch #\newline)
+                             (eq? ch #\return))
+                         (do-line-end ch))
+                        
+                        ((eq? state 'line-end)
+                         (lp i 'start r l))
+
+                        ((eq? ch delimiter)
+                         (do-delim ch))
+
+                        ((eq? state 'field-end)
+                         (raise-
+                          (Error "no ending char after field-end")))
+                            
+                        ((or (eq? ch #\space) (eq? ch #\tab))
+                         (do-whitespace ch))
+                          
+                        ((eq? ch quotechar)
+                         (do-quotechar ch))
+
+                        ((eq? ch escapechar)
+                         (do-escape ch))
+                      
+                        ((eq? state 'numeric)
+                         (if (or (eq? ch #\.)
+                                 (eq? ch #\-)
+                                 (eq? ch #\e)
+                                 (eq? ch #\E)
+                                 (char-numeric? ch))
+                             (lp (+ i 1) state (cons ch r) l)
+                             (raise-
+                              (Error "nonumeric in numeric field"))))
+                          
+                        ((eq? state 'start)
+                         (cond
+                          ((eq? quoting 'all)
+                           (raise-
+                            (Error
+                             "nonquoted field when all should be quoted")))
+                              
+                          ((eq? quoting 'nonnumeric)
+                           (lp i 'numeric r l))
+
+                          (else
+                           (lp i 'normal r l))))
+
+                        ((or (eq? state 'quote) (eq? state 'normal))
+                         (lp (+ i 1) state (cons ch r) l))
+
+                        ((eq? state 'doublequote)
+                         (raise- (Error "spur char after end of quote")))
+
+                        ((pair? state)
+                         (lp (+ i 1) (cdr state) r l))
+                        
+                        (else
+                         (error "Bug in csv reader"))))
+                     (lp0 state r l))))))))))))
+              
+(define-python-class writer ()                                 
+  (define __init__
+    (lam (self csvfile (= dialect "excel") (** fmtparams))        
+         (set! dialect (if (string? dialect)
+                           (get_dialect dialect)
+                           dialect))
+         (let* ((hash  (make-hash-table)))
+           (hash-set! hash 'delimiter
+                      (chr (py-get fmtparams "delimiter" e)
+                           (ref    dialect   'Delimiter  e)
+                           ","))
+         
+           (hash-set! hash 'doublequote
+                      (oor (py-get fmtparams "doublequote" e)
+                           (ref    dialect   'doublequote  e)
+                           #t))
+         
+           (hash-set! hash 'escapechar
+                      (chr (py-get fmtparams "escapechar" e)
+                           (ref    dialect   'escapechar  e)
+                           None))
+         
+           (hash-set! hash 'lineterminator
+                      (str (py-get fmtparams "lineterminator" e)
+                           (ref    dialect   'lineterminator  e)
+                           "\r\n"))
+         
+           (hash-set! hash 'quotechar
+                      (chr (py-get fmtparams "quotechar" e)
+                           (ref    dialect   'quotechar  e)
+                           "\""))
+           
+           (hash-set! hash 'quoting
+                      (oor (py-get fmtparams "quoting" e)
+                           (ref    dialect   'quoting  e)
+                           QUOTE_MINIMAL))
+         
+           (hash-set! hash 'skipispace
+                      (oor (py-get fmtparams "skipinitialspace" e)
+                           (ref    dialect   'skipinitialspace  e)
+                           #t))
+         
+           (hash-set! hash 'strict
+                      (oor (py-get fmtparams "strict" e)
+                           (ref    dialect   'strict  e)
+                           #f))
+
+           (set self 'csvfile csvfile)
+           (set self '_hash   csvfile))))
+
+  (define writerow
+    (lambda (self l)
+      (define (write x)
+        ((ref (ref self 'csvfile) 'write) x))
+
+      (define (get-str x) (if (string? x) x (scm-str x)))
+      
+      (let* ((hash           (ref self '_hash))
+             (delimiter      (hash-ref hash 'delimiter))
+             (doublequote    (hash-ref hash 'doublequote))
+             (escapechar     (hash-ref hash 'escapechar))
+             (lineterminator (hash-ref hash 'lineterminator))
+             (quotechar      (hash-ref hash 'quotechar))
+             (quoting        (hash-ref hash 'quoting))
+             (skipispace     (hash-ref hash 'skipinitialspace))
+             (strict         (hash-ref hash 'strict))
+             (terms          (string->list lineterminator)))
+
+        (define (has-escape-1 x)
+          (let ((n (len x)))
+            (let lp ((i 0))
+              (if (< i n)
+                  (let ((a (string-ref x i)))
+                    (if (or (eq? a #\,) (member a terms))
+                        #t
+                        (lp (+ i 1))))
+                  #f))))
+        
+        (define (has-escape-2 x)
+          (let ((n (len x)))
+            (let lp ((i 0))
+              (if (< i n)
+                  (let ((a (string-ref x i)))
+                    (if (or (eq? a quotechar)
+                            (eq? a delimiter)
+                            (member a terms))
+                        #t
+                        (lp (+ i 1))))
+                  #f))))
+
+        (define (quote-it x)
+          (let ((n (len x)))
+            (let lp ((i 0) (r '()))
+              (if (< i n)
+                  (let ((a (string-ref x i)))
+                    (cond
+                     ((eq? a quotechar)
+                      (if doublequote
+                          (lp (+ i 1) (cons* a a r))
+                          (lp (+ i 1) (cons* a escapechar r))))
+                     ((eq? a escapechar)
+                      (lp (+ i 1) (cons* a a r)))
+                     (else
+                      (lp (+ i 1) (cons a r)))))
+                  (list->string (reverse! r))))))
+
+        (define (is-numeric x)
+          (catch #t
+            (lambda ()
+              (string->number x))
+            (lambda x #f)))
+          
+        
+
+        (for ((x : l)) ((r '()))
+             (let/ec ret
+               (cons
+                (cond
+                 ((eq? quoting 'none)
+                  (let ((x (get-str x)))
+                    (if (has-escape-1 x)
+                        (if strict
+                            (raise (Error "None quoting and nonspecial chars"))
+                            (ret r))
+                        x)))
+                 
+                 ((eq? quoting 'nonnumeric)
+                  (let ((x (get-str x)))
+                    (aif it (is-numeric x)
+                         (number->string it)
+                         (quote-it x))))
+                
+                 ((eq? quoting 'none)
+                  (get-str x))
+                 
+                 ((eq? quoting 'minimal)
+                  (let ((x (get-str x)))
+                    (if (has-escape-2 x)
+                        (quote-it x)
+                        x))))
+                r)
+               #:final
+               (write
+                (string-join
+                 (reverse
+                  (cons lineterminator r)) (string-ref delimiter 0)))))))))
+
diff --git a/modules/language/python/module/csv.py b/modules/language/python/module/csv.py
index 0349e0b..79c429f 100644
--- a/modules/language/python/module/csv.py
+++ b/modules/language/python/module/csv.py
@@ -1,3 +1,4 @@
+module(csv)
 
 """
 csv.py - read/write/investigate CSV files